Evaluation of geographic variations in cancer rates may suggest clues to the roles of environmental or cultural influences. The identification of regions at notably high or low risk may indicate areas where more intensive studies may be particularly fruitful. We have completed preparations for the production of a new atlas of cancer mortality in the United States during 1970-92. We edited data files pertaining to more than 8.5 million whites and 1.0 million blacks who died from cancer and prepared the corresponding required estimates of person-years at risk. We developed software referred to as the "Mortality Rate Generator" program to calculate observed and expected counts, age-adjusted rates, and confidence limits by cancer, race, sex, time period, and geographic area. Using special graphics software for Windows on a personal computer, we have generated more than 140 maps at the county or State Economic Area level that will be included in the atlas. The analysis of these maps is in progress. The map portraying breast cancer mortality among white females documented the continuing high risks among women in the northeast and low risks across the south; such data provided the basis for an investigation of the degree to which geographic variations in the prevalence of breast cancer risk factors could account for the mortality patterns. Maps were used to investigate the geographic variation in non-Hodgkin's lymphoma rates and the potential role of sunlight exposure; non-Hodgkin's lymphoma rates were higher in the north than the south among both white men and women, in contrast to higher sunlight levels in the south than in the north. We are studying the relationships of melanoma rates and trends to ultraviolet-B radiation levels. We are evaluating methods to make the rates and maps available on the internet, and an example was distributed on the internet for display at a workshop sponsored by the Department of Health and Human Services. A poster session describing the atlas was presented at a symposium on mapping in Tampa, Florida.